Saikia et al. SpringerPlus (2015) 4:827 DOI 10.1186/s40064-015-1607-1
Open Access
RESEARCH
Prediction of extubation failure in newborns, infants and children: brief report of a prospective (blinded) cohort study at a tertiary care paediatric centre in India Bedangshu Saikia1*, Nirmal Kumar1 and Vishnubhatla Sreenivas2
Abstract Background: Extubation failure (EF), defined as need for re-intubation within 24–72 h, is multifactorial. Factors predicting EF in adults generally are not useful in children. Objective: To determine the factors associated with EF and to facilitate prediction of EF in mechanically ventilated infants and children less than 12 years of age. Material and Methods: Design Prospective cohort study. Setting PICU and NICU of a multispecialty tertiary care institute. Patients All consecutive newborns, infants and children, who remained on the ventilator for more than 12 h, were included. Patients with upper airway obstruction, neuromuscular disorders, complex anatomic malformations, accidental extubation, tracheostomy or death before extubation were excluded. Methods The pre-extubation clinical, laboratory and ventilatory parameters were collected for 92 cases over a one and half year period. The EF rate was calculated for each variable using STATA 9. All the treating physicians were blinded to the data collection procedure. Measurements and Results: Demographics were comparable between the extubation success and EF groups. Respiratory failure was the main cause requiring ventilation (46.74 %, 95 % CI 0.37–0.57) as well as EF (30.23 %, 95 % CI 0.08–0.23). 76.92 % (95 % CI 0.58–0.89) of patients that failed extubation had alterations in respiratory effort, 38.46 % (95 % CI 0.22–0.57) each had either poor or increased respiratory effort. Poor cough reflex (p = 0.001), thick endotracheal secretions (p = 0.02), failed spontaneous breathing trial (SBT) (p = 0.001) and higher rapid shallow breathing index (RSBI) (p = 0.001) were found to be associated with EF. Conclusions: Paediatric EF is multifactorial. Increased or poor respiratory effort and failed SBT are potential factors in deciding re-intubation. Increased RSBI, poor cough reflex and thick. Keywords: Extubation failure, Respiratory effort, Poor cough reflex, Thick secretions, Spontaneous breathing trial, Rapid shallow breathing index Background After resolution of illness, mechanically ventilated patients are disconnected from the ventilator; extubation is the final step in this process. Extubation failure (EF) is defined as an inability to sustain spontaneous breathing *Correspondence:
[email protected] 1 Department of Paediatrics and Neonatology, St Stephens Hospital, Tis Hazari, New Delhi 110054, India Full list of author information is available at the end of the article
and need for re-intubation within 24–72 h after extubation (Rothar and Epstein 2003). Prediction of EF is essential, as both delayed and failed extubation have detrimental consequences (Rothar and Epstein 2003). The incidence of EF varies between 2 to 47 % (Rothar and Epstein 2003; Kulkarni and Aggarwal 2008). It can be as high as 22 to 28 % in premature neonates (Khan et al. 1996). A variety of patho-physiologic causes lead to EF. The prediction of EF is difficult (Rothar and Epstein 2003;
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Saikia et al. SpringerPlus (2015) 4:827
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Kulkarni and Aggarwal 2008). Newth et al. reported limited guidance on paediatric weaning and extubation from their literature review (Newth et al. 2009). Indices developed to predict weaning and extubation success (ES) are no better than clinical judgment (Newth et al. 2009). Similarly, Leclerc and Schindler observed that adult weaning predictors proposed by the Task Force of the American College of Chest Physicians have very poor predictive power in children (Yang and Tobin 1991; Leclerc et al. 2005; Schindler. 2005). We undertook this study in newborns, infants and children to explore factors that may predict EF.
spontaneous breathing trial (SBT), rapid shallow breathing index (RSBI) and use of bubble CPAP following extubation. These parameters were measured pre-extubation, post-extubation (whenever necessary), and at the time of any re-intubation.
Methods This prospective cohort study was conducted at PICU and NICU of a multispecialty tertiary care institute in India over a period of one and half years (December 2008 to May 2010). All consecutive infants and children less than 12 years of age, admitted and ventilated for more than 12 h were included in the study. Patients with upper airway obstruction, accidental extubation, tracheostomy, or death before extubation were excluded. The sample size was calculated using 95 % confidence interval, 10 % margin of error and 30 % estimated incidence of EF in the study area. We did a retrospective analysis of PICU register books to find out the incidence of EF in our PICU. We looked at the previous 2 years data and approximated the incidence of EF in our PICU to be around 30 %. We used the formula, n = t2 x p (1−p) x 1/m2, where ‘n’ is required sample size, ‘t’ is confidence level at 95 %, ‘p’ is estimated incidence of EF in the project area and ‘m’ is margin of error at 10 % (Calculating the sample size—IFAD). This gave us the minimum sample required for the study as 81 and we collected data for 92 patients. The research team was not involved directly in the clinical care. All decisions related to patient’s care were taken by the treating physician and they were blinded to data collection and analysis procedure. The parameters that were collected were divided into: (1) Demographic data: Age, sex, weight, diagnosis on admission, indication for ventilation and duration of intubation, (2) Clinical parameters: Haemoglobin concentration, heart rate, spontaneous respiratory rate, blood pressure, peripheral oxygen saturation (SpO2), work of breathing, presence of cough reflex, amount and consistency of secretion, use of ionotropes, use of sedation and use of dexamethasone, (3) Blood gas parameters (venous gases): pH, partial pressure of carbon dioxide (PCO2), bicarbonate (HCO3−), base excess (BE), lactate and (4) Ventilatory parameters: Ventilator mode, ventilator rate, peak inspiratory pressure (PIP), positive end-expiratory pressure (PEEP), fraction of inspired oxygen (FiO2), inspiratory time (Ti), expiratory time (Te),
Data analysis
Derived parameters
Indices that incorporated more than one measurement of respiratory function i.e., mean airway pressure {MAP = [(PIP − PEEP) (Ti)/Ti + Te] + PEEP} and ventilator index {VI = [Ventilatory rate × (PIP − PEEP)*PCO2]/1000} were calculated. EF rate was calculated for each variable using the statistical software STATA 9, version 17. Data was presented in frequency percentage with confidence intervals and mean (SD) and median (minimum–maximum). In the continuous parameters, average (mean/median) between the two groups was compared by using t test and Wilcoxan rank sum test. In the categorical variable, two groups were compared by using Chi-square and Fisher’s exact test. p value
